senator carden, glad to have you here, sir. >> alex, good to be with you. >> edward snowden released what he called this manifesto for the truth. he says current debates about spying just prove his revelations are helping bring about change. what's your response to that? >> mr. snowden has caused real damage to this country. the manner in which he has conducted these releases have compromised our national security. as senator feinstein said, there's a way in which a whistleblower can get information to us. we want to make sure there's adequate oversight on the powers of the intelligence community. we need the right balance to keep us safe and protect the rights of americans. so there's concern on how we collect data, but for a person who has been given that access and trust on his own to do this type of release is detrimental to our country. >> sir, as you serve on the senate foreign relations committee, i know you're privy to things we are not necessarily. do you believe what we know so far is merely the tip of the iceberg? >> no, i feel pretty confident that there is adequate overs